{
 "metadata": {
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.8.2-final"
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  "orig_nbformat": 2,
  "kernelspec": {
   "name": "Python 3.8.2 64-bit ('stackoverflow': conda)",
   "display_name": "Python 3.8.2 64-bit ('stackoverflow': conda)",
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 },
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 "cells": [
  {
   "source": [
    "# Named tuples and dataclasses"
   ],
   "cell_type": "markdown",
   "metadata": {}
  },
  {
   "source": [
    "A quick review of named tuples (standad and typed) and dataclasses.\n",
    "\n",
    "From the [Data Science from Scratch book](https://www.oreilly.com/library/view/data-science-from/9781492041122/)."
   ],
   "cell_type": "markdown",
   "metadata": {}
  },
  {
   "source": [
    "## `namedtuple`"
   ],
   "cell_type": "markdown",
   "metadata": {}
  },
  {
   "source": [
    "Similar to dictionaries but\n",
    "\n",
    "- fields are named\n",
    "- values are immutable"
   ],
   "cell_type": "markdown",
   "metadata": {}
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "from collections import namedtuple\n",
    "import datetime"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "StockPrice = namedtuple('StockPrice', ['symbol', 'date', 'closing_price'])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "output_type": "execute_result",
     "data": {
      "text/plain": [
       "type"
      ]
     },
     "metadata": {},
     "execution_count": 3
    }
   ],
   "source": [
    "type(StockPrice)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "output_type": "execute_result",
     "data": {
      "text/plain": [
       "StockPrice(symbol='MSFT', date=datetime.date(2018, 12, 14), closing_price=106.03)"
      ]
     },
     "metadata": {},
     "execution_count": 4
    }
   ],
   "source": [
    "price = StockPrice('MSFT', datetime.date(2018, 12, 14), 106.03)\n",
    "price"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "output_type": "execute_result",
     "data": {
      "text/plain": [
       "__main__.StockPrice"
      ]
     },
     "metadata": {},
     "execution_count": 5
    }
   ],
   "source": [
    "type(price)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "output_type": "execute_result",
     "data": {
      "text/plain": [
       "('MSFT', datetime.date(2018, 12, 14), 106.03)"
      ]
     },
     "metadata": {},
     "execution_count": 6
    }
   ],
   "source": [
    "price.symbol, price.date, price.closing_price"
   ]
  },
  {
   "source": [
    "## `NamedTuple`"
   ],
   "cell_type": "markdown",
   "metadata": {}
  },
  {
   "source": [
    "Simlar to `namedtuple` but\n",
    "\n",
    "- it is a class\n",
    "- fields have to be typed\n",
    "- as it is a class, it can have methods"
   ],
   "cell_type": "markdown",
   "metadata": {}
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [],
   "source": [
    "from typing import NamedTuple"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [],
   "source": [
    "class StockPrice(NamedTuple):\n",
    "    symbol: str\n",
    "    date: datetime.date\n",
    "    closing_price: float\n",
    "\n",
    "    def is_high_tech(self) -> bool:\n",
    "        return self.symbol in ['MSFT', 'GOOG', 'FB', 'AMZN', 'AAPL']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "output_type": "execute_result",
     "data": {
      "text/plain": [
       "StockPrice(symbol='MSFT', date=datetime.date(2019, 12, 14), closing_price=106.83)"
      ]
     },
     "metadata": {},
     "execution_count": 9
    }
   ],
   "source": [
    "stockprice = StockPrice('MSFT', datetime.date(2019, 12, 14), 106.83)\n",
    "stockprice"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "output_type": "execute_result",
     "data": {
      "text/plain": [
       "True"
      ]
     },
     "metadata": {},
     "execution_count": 10
    }
   ],
   "source": [
    "stockprice.is_high_tech()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "output_type": "execute_result",
     "data": {
      "text/plain": [
       "False"
      ]
     },
     "metadata": {},
     "execution_count": 11
    }
   ],
   "source": [
    "StockPrice('TOOT', 12, 12).is_high_tech()"
   ]
  },
  {
   "source": [
    "## Dataclasses"
   ],
   "cell_type": "markdown",
   "metadata": {}
  },
  {
   "source": [
    "Similar to `NamedTuple` but\n",
    "\n",
    "- fields are mutable"
   ],
   "cell_type": "markdown",
   "metadata": {}
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [],
   "source": [
    "from dataclasses import dataclass"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [],
   "source": [
    "@dataclass\n",
    "class StockPrice2:\n",
    "    symbol: str\n",
    "    date: datetime.date\n",
    "    closing_price: float\n",
    "\n",
    "    def is_high_tech(self) -> bool:\n",
    "        return self.symbol in ['MSFT', 'GOOG', 'FB', 'AMZN', 'AAPL']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "output_type": "execute_result",
     "data": {
      "text/plain": [
       "StockPrice2(symbol='MSFt', date=datetime.date(2018, 12, 14), closing_price=106.03)"
      ]
     },
     "metadata": {},
     "execution_count": 14
    }
   ],
   "source": [
    "stockprice2 = StockPrice2('MSFt', datetime.date(2018, 12, 14), 106.03)\n",
    "stockprice2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "output_type": "execute_result",
     "data": {
      "text/plain": [
       "53.015"
      ]
     },
     "metadata": {},
     "execution_count": 15
    }
   ],
   "source": [
    "stockprice2.closing_price /= 2\n",
    "stockprice2.closing_price"
   ]
  },
  {
   "source": [
    "For `NamedTuple` this does not work"
   ],
   "cell_type": "markdown",
   "metadata": {}
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "output_type": "error",
     "ename": "AttributeError",
     "evalue": "can't set attribute",
     "traceback": [
      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[0;31mAttributeError\u001b[0m                            Traceback (most recent call last)",
      "\u001b[0;32m<ipython-input-16-7ab00711d514>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mstockprice\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mclosing_price\u001b[0m \u001b[0;34m/=\u001b[0m \u001b[0;36m2\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
      "\u001b[0;31mAttributeError\u001b[0m: can't set attribute"
     ]
    }
   ],
   "source": [
    "stockprice.closing_price /= 2"
   ]
  }
 ]
}